1,007 research outputs found
A facile one pot synthesis of pyrazolo[3,4-D] pyrimidines
The reaction of 6-hydrazino uracils 1 with isocyanates 2 gave access to an efficient one-pot synthesis of pyrazolo[3,4-
d]pyrimidines 3 in excellent yield
Studies on uracils : a facile one-pot synthesis of oxazino[4,5- d]-, pyrano[2,3-d]-, pyrido[2,3-d]- and pyrimido[4,5-d]pyrimidines using microwave irradiation in the solid state
—N,N-Dimethyl-5-formylbarbituric acid 1 reacts with maleimide 2 and phenyl isocyanate/phenyl isothiocyanate 4 under
microwave-assisted conditions in the solid phase to afford pyrano[2,3-d]pyrimidines3 and oxazino[4,5-d]pyrimidines5 in excellent
yields. Under identical conditions, N,N-dimethyl-6-amino-5-formyluracil 6 reacts with 2 and 4 to give pyrido[2,3-d]pyrimidine
derivative 7 and pyrimido[4,5-d]pyrimidines 8 in high yield
Mills hemiparetic or hemiplegic variant of amyotrophic lateral sclerosis
Mills hemiplegic variant of Amyotrophic lateral sclerosis (ALS) is a gradually progressive, spastic ascending or descending hemiparesis or hemiplegia without any sensory involvement. Authors presented a 47 years old female with history of gradually progressive left sided wasting of muscles including the tongue, left hemiparesis along with dysarthria and fasciculation’s of tongue and left sided muscles with left sided cortico-spinal tract signs of 2 years duration. There were no sensory as well as bowel bladder involvement. Her cognition was intact. Relevant blood and CSF examinations were within normal limit. MRI Brain and whole spine were unremarkable. Nerve conduction study was essentially normal. Electromyography(EMG) showed chronic denervation potentials which is in accordance to Revised El Escorial criteria, 2015 for the diagnosis of this extremely uncommon entity- Mills hemiplegic variant of ALS. The major challenge in diagnosis of this disease entity is to exclude other diseases/disorders that may mimic its symptomatology
Studies on uracils : synthesis of novel pyrido[2,3-d]- pyrimidine oxides via ring transformation of isoxazolo[3,4-d]pyrimidine
The reaction of isoxazolo[3,4-d]pyrimidine 1 and cyanoolefins 2 in the presence of triethylamine (Et3N) as a catalyst
afforded an unprecedented one-pot synthesis of biologically important pyrido[2,3-d]pyrimidine oxides 3 in excellent yields
Grand unification in the minimal left-right symmetric extension of the standard model
The simplest minimal left-right symmetric extension of the standard model is
studied in the high energy limit, and some consequences of the grand
unification hypothesis are explored assuming that the parity breaking scale is
the only relevant energy between the electro-weak scale and the unification
point. While the model is shown to be compatible with the observed neutrino
phenomenology, the parity breaking scale and the heavy boson masses are
predicted to be above 10^7 TeV, quite far from the reach of nowadays
experiments. Below that scale only an almost sterile right handed neutrino is
allowed with a mass M \approx 100 TeV
Cleaning of Indian coals by agglomeration with xylene and hexane
A laboratory scale agglomeration process has been undertaken for
cleaning Indian coals using oils namely, xylene and hexane.
Maximum organic matter recovery for xylene has been found to be
91.9% whereas with hexane, the value is 54.7% on a dry basis. The
highest ash rejection values with xylene (90.7%) and with hexane
(89.7%) are almost same. Promising results for rejection of metals
(Fe, Mg and Zn) have been observed. It has been found that xylene
is more selective than hexane for the agglomeration process.
Knowledge gained from this study will be helpful for technological
advancement of this kind of work
Reactor mixing angle from hybrid neutrino masses
In terms of its eigenvector decomposition, the neutrino mass matrix (in the
basis where the charged lepton mass matrix is diagonal) can be understood as
originating from a tribimaximal dominant structure with small deviations, as
demanded by data. If neutrino masses originate from at least two different
mechanisms, referred to as "hybrid neutrino masses", the experimentally
observed structure naturally emerges provided one mechanism accounts for the
dominant tribimaximal structure while the other is responsible for the
deviations. We demonstrate the feasibility of this picture in a fairly
model-independent way by using lepton-number-violating effective operators,
whose structure we assume becomes dictated by an underlying flavor
symmetry. We show that if a second mechanism is at work, the requirement of
generating a reactor angle within its experimental range always fixes the solar
and atmospheric angles in agreement with data, in contrast to the case where
the deviations are induced by next-to-leading order effective operators. We
prove this idea is viable by constructing an -based ultraviolet
completion, where the dominant tribimaximal structure arises from the type-I
seesaw while the subleading contribution is determined by either type-II or
type-III seesaw driven by a non-trivial singlet (minimal hybrid model).
After finding general criteria, we identify all the symmetries
capable of producing such -based minimal hybrid models.Comment: 18 pages, 5 figures. v3: section including sum rules added, accepted
by JHE
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